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Cologuard is a stool DNA test - that patients can use at home - that screens for the presence of colon cancer and precancers. The Food and Drug Administration approved the test on Monday.
(Exact Sciences)

The Food and Drug Administration this week approved the first stool-based colorectal screening test approved for the detection of colorectal cancer and precancerous growths that can be used in the privacy of one's home. The technology used to create the test emerged more than a decade ago from labs at University Hospitals Case Medical Center and Case Western Reserve University.

Those who would rather avoid having a colonoscopy now have the option of Cologuard, a noninvasive test that detects the presence of red blood cells and DNA mutations that may indicate the presence of certain kinds of abnormal growths.

People can order the test through their physician or other health care provider, who can have the test sent directly to patients' homes. The time frame for sending the tests is still being determined, said a spokeswoman for Exact Sciences, which makes the test.

Colorectal cancer screening

The American Cancer recommends that adults should begin colorectal cancer screening at age 50 using one of the following tests: flexible sigmoidoscopy (every five years), colonoscopy (every 10 years), CT (virtual) colonoscopy (every five years), take-home fecal occult blood test or fecal immunochemical test (every year), or stool DNA test. If the results of any of the screening tests are positive, a colonoscopy test should be done for confirmation.

The patient collects a stool sample in the Cologuard Collection Kit and sends the kit back to the Exact Sciences lab in Madison, Wisconsin for testing through a pre–paid mailer. Test results are available in as little as two weeks.

"While the science behind stool-based DNA screening is complex, the specimen collection process is very simple and patient-friendly," states the company's website. "No bowel preparation. No dietary restrictions."

The test is an alternative to colonoscopy, considered the gold-standard screening for colorectal cancer, for people who can't or won't tolerate colonoscopy and the prep that goes with it.

Cologuard is a second-generation successor to ColoSure, a stool DNA, or sDNA test, that Exact Sciences developed with UH and CWRU researchers.

In 2003, Dr. Sanford Markowitz, professor of cancer genetics at CWRU School of Medicine and an oncologist at UH Seidman Cancer Center, led a team that helped develop the technology behind the stool DNA test.

They discovered a specific DNA change that takes place in colorectal cancers. They then created techniques for detecting the DNA change when it was expelled from the body in feces.

CWRU licensed the rights to Exact Science for further development. Another company marketed the test, which didn't require FDA approval because it was a laboratory-developed (or "home brewed") test, but took it off the market for further research.

Dr. Sanford MarkowitzUH

Cologuard is based on ColoSure in that Cologuard is also based on detecting DNA changes in the stool, Markowitz said.

"We were the first to discover that we could detect colorectal cancer in methylated DNA in stool of colon cancer patients," he told The Plain Dealer.

However, the specific methylated DNA used in the early test has changed in Cologuard, he said.

The safety and effectiveness of Cologuard was established in a clinical trial that screened more than 10,000 people and compared Cologuard to the fecal immunochemical test that detects blood in the stool. Cologuard accurately detected cancers and advanced adenomas more often than FIT; The sDNA test, however, was less accurate than FIT (87 percent versus 95 percent) at correctly identifying subjects who did not have colorectal cancer or precancers.

On Monday, the Centers for Medicare & Medicaid Services issued a memo proposing coverage of Cologuard for all Medicare and Medicaid beneficiaries age 50-85 who meet certain criteria.

CMS would cover the cost of the test once every three years for people who have no sign or symptoms of colorectal disease; and who have an average risk of developing colorectal cancer – meaning no family history or previous diagnosis of polyps or colorectal cancer; and no history of inflammatory bowel disease.

For people without insurance coverage, the test will cost $599.

Markowitz, who also is head of the Cancer Genetics Program at the Case Comprehensive Cancer Center, said he envisions using sDNA in concert with colonoscopy, perhaps 12 months after colonoscopy to affirm a negative test.

"We still need to do more studies to understand exactly how to use Cologuard and how to use colonoscopy," he said. "My own guess is that we're going to wind up using both of them."

Since 2011, UH has enrolled 450 patients in a clinical trial testing the effectiveness of sDNA compared with colonoscopy. Patients are given both. It's one of several studies of the GI SPORE (Specialized Program of Research and Excellence)- GI Cancers Research Center at CWRU, created with a grant from the National Institutes of Health.

"The questions we don't have the answers yet for are, how often should we repeat [sDNA]?" Markowitz said. "What should we do if the test is positive? We hope to have answers to those questions within a year."

Clues to Cancer: Patients, doctors on road to discovery

For 10 months, Plain Dealer reporter Angela Townsend and photographer Lynn Ischay followed 9 patients through their journey as study participants in Phase 1 trials at University Hospitals. We tell their stories here.

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